8/30/2019 9:52 AM PT

9:52 AM PT -- Concepts for the Inspire Change apparel are still being developed ... according to sources familiar with the deal. We're told the line will be available to the public in October.

For Jay-Z, the best defense is a good offense -- he's wasting no time putting his controversial NFL partnership to work by launching a new apparel line to fund social change ... and enlisting his pal, Meek Mill.

The NFL and Jay's Roc Nation just announced a new Inspire Change apparel line and a music showcase called Songs of the Season. The music part of that deal will begin with Meek, Meghan Trainor and Rapsody performing at the NFL Kickoff Event in Chicago on Sept. 5.

Meek and Rapsody are Roc Nation clients, but Meghan is not ... which shows that despite facing a wave of criticism, Jay still has plenty of entertainers willing to support his NFL venture. All 3 artists are the first Inspire Change advocates.

The bigger part of the deal, though, is the apparel line -- because it seems to have Jay's fingerprint all over it. After successfully launching his Rocawear and Paper Planes (that Roc Nation logo you see everywhere) ... he knows there's big money in clothing and caps.

Roc Nation and the league say the revenue from Inspire Change apparel will fund Inspire Change programs across the U.S. -- with a focus on "economic empowerment, police and community relations, and criminal justice reform."